This invention is directed to a flotation system for a wave harvesting device. The flotation system includes a conical shaped float having a submergible wave energy harvesting device attached to its apex such that the apex of the conical shape is downwardly oriented and the base of the conical shape is upwardly oriented.
With the introduction of utilization of electrical energy in the late 1800s, man has sought a number of ways to generate electricity. One of the earliest ways examined for generating electrical power was wave energy. Not too much longer thereafter, however, petroleum became very available, and this, in combination with hydroelectrical electrical generation, soon relegated wave energy to the position of being only a curiosity.
With the recent realizations that fossil fuel sources are of a limited supply, alternative forms of electrical energy generation have been sought. In my U.S. Pat. No. 4,462,211, I describe an apparatus for harvesting wave energy. The apparatus or device described therein takes advantage of the fact that wave energy for the most part is a surface phenomena, and, depending upon the depth of the water, water below the surface does not necessarily move in association with the wave motion on the top of the surface of the body of water.
The device I describe in my U.S. Pat. No. 4,462,211, utilizes two counter-rotating turbines which, in turn, rotate counter-rotating shafts leading from the turbines to the surface of the water.
The counter-rotating turbines of the device of my patent, U.S. Pat. No. 4,462,211, are raised and lowered at a depth below the surface of the water by wave action of a float floating on the surface of the water to which the shafts are attached. At the surface, motion from one of the shafts is reversed and combined with rotation of the other shafts and is transferred to a generator for the generation of electrical energy.
The wave harvesting device described in my patent is attached to an essentially flat surface float. As described in my U.S. Pat. No. 4,462,211, the turbines and the shafts of that device essentially remain in a vertical orientation irrespective of movement of the float as it follows the wave action on the surface of the body of water.
Dating back to antiquity, many designs for floats have been utilized. While platform floats, such as the one I describe in my U.S. Pat. No. 4,462,211, have a large surface area, at all times they have a constant displacement. Because of this constant displacement and their own inertia, when they are subjected to a rising wave, they tend to sink into the wave. And when they are subjected to a descending wave, the wave tends to drop out from beneath them. This same effect is true of other floats or buoys which also have a substantially constant displacement. This mitigates the wave action, tending to decrease the energy harvesting action of any device attached to these floats.
Because waves vary in their length from nothing in calm water to very long waves, a flat float is subjected to varying horizontal forces. In order to maintain the integrity of the float during the most severe conditions, ribs, keels, bulkheads, or other supporting structures must be engineered into flat floats. Inevitably, with the addition of strength also comes the addition of weight, and the float must support not only the wave energy harvesting device beneath it, but its own structural weight. This further mitigates the efficiency of the float.